18684139 has 8 divisors (see below), whose sum is σ = 19856880. Its totient is φ = 17580448.

The previous prime is 18684121. The next prime is 18684161. The reversal of 18684139 is 93148681.

It is not a de Polignac number, because 18684139 - 2¹¹ = 18682091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18684539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3012 + ... + 6814.

It is an arithmetic number, because the mean of its divisors is an integer number (2482110).

Almost surely, 2^18684139 is an apocalyptic number.

18684139 is a deficient number, since it is larger than the sum of its proper divisors (1172741).

18684139 is an frugal number, since it uses more digits than its factorization.

18684139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3854 (or 3820 counting only the distinct ones).

The product of its digits is 41472, while the sum is 40.

The square root of 18684139 is about 4322.5153556697. The cubic root of 18684139 is about 265.3532206853.

The spelling of 18684139 in words is "eighteen million, six hundred eighty-four thousand, one hundred thirty-nine".